High speed nailmaker feed mechanism



April 30, 1957 J. H. FRIEDMAN 2,790,541

HIGH SPEED NAILMAKER FEED MECHANISM Filed Apf'il 2. 1953 s Sheets-Sheet 1 I N VEN TOR. JOHN H. FRIEDMAN ATmP/VEYS April 30, 1957 J. H. FRIEDMAN HIGH SPEED NAILMAKER FEED MECHANISM 3 Shets-Sheet 2 Filed April 2, 1953 WEE: m W/m/ I m s o Y E5 E Vm N m m ,H. T N V r A April 30, 1957 J. H. FRIEDMAN s Shets-Sheet s EHGH SPEED NAILMAKER FEED MECHANISM Eohn H. Friedman, Tihin, Ohio, assignor to The National Machinery Company, Titlin, Ohio, a corporation of Qhio Application April 2, 1953, Serial No. 346,369

4 Ciaims. (CL-203-166) This invention relates generally to feed mechanisms for high speed forging machines and more particularly to a feed mechanism for high speed nail making machines wherein wire stock is advanced between the stock gripping dies, headed and formed into a complete nail.

A principal object of the present invention is to provide a feed mechanism which is so arranged so as to feed stock at a faster rate than has been obtainable in machines of the prior art.

Another object of the present invention is to provide a feed mechanism which Will positively feed Wire stock at a high rate of speed and which will not bend or ad'- versely affect the stock being fed.

Another object of this invention is to provide a feed mechanism wherein the stroke of the mechanism may be adjusted while the machine is in operation.

It is another object of this invention to provide a feed mechanism with a positive action at all times.

Another object of this invention is to provide a feed mechanism which reduces the tendency of the stock to am.

It is also an object of this invention to provide the above advantages in a mechanism which is relatively immune to wear and which will thereby give a longer trouble-free service life.

The mechanism according to this invention is adapted for use in :a nail making machine similar to the machine disclosed in my co-pending application Serial No. 310,461, filed September 19, 1952, which discloses a nail making machine capable of manufacturing nails at a rate substantially higher than the machines disclosed in the prior art. With the tremendous increase in output accomplished with the machine disclosed in my co-pending application cited above, it became apparent that the conventional methods of powering the feed mechanism for feeding the stock into the machine were unsatisfactory.

In the past the feed mechanisms normally operated with substantially a simple harmonic motion wherein the stock was advanced through substantially half of the cycle of the machine and the feed mechanism returned to its initial position through the other half of the cycle of the machine.

The feed mechanism according to this invention provides a non-uniform motion wherein the feed carriage feeds the wire stock forward into the machine during a period of the machines cycle substantially less than one half of the complete cycle. The feed carriage remains substantially stationary in the rearward position through a large portion of the cycle of a nail making machine during which time the previously fed stock may easily be headed and pointed. When the feed carriage starts moving forward the wire stock is clamped by gripping wedges mounted on the feed carriage. This causes the wire to be fed into the machine as the feed carriage moves from the rearward position to the forward position. A spring loaded mechanism is provided to urge the wedgesinto nited States Patent 2,190,541 l atented Apr. 30,

engagement with the stock :and is arranged so a maximum force is applied to the wedges when the feed carriage is in the rearward position. When the feed carriage reaches the forward position it rapidly decelerates until the carriage comes to rest after which a very rapid acceleration takes place toward the rearward position. This rapid reversal of the feed carriage causes the momentum of the wedges to assist in releasing the wire stock thereby insuring a complete release of thestock at the forward position.

Because the feed carriage accelerates relatively gr'a'dually as it initiates the feeding of the stock the tendency of the stock between the gripping wedges andthe dies of the machine to bend and jam is substantially reduced thereby eliminating difliculties which have been encountered in the past in high speed feed mechanisms.

The mechanism accordingto this invention also provides for adjusting'the length of the feed stroke while the machine is in operation thereby eliminating the necessity of shutting down the machine for such adjustments. This arrangement, of course, has obvious advantages in that it makes it possible for the operator of 'themachine to determine the efiect of the adjustment immediately, and eliminates the shut down time previously necessary for the adjustments.

The foregoing and other objects and advantages will become apparent in View of the following 'de'sciip'tion taken in conjunction with the drawings, wherein:

Fig. l is a side elevation of a nail making machine showing the driving mechanism embodying this inven- 'tion;

Fig. 2 is an enlarged side elevation showing the details of the linkage adjacent to the feed mechanism;

Fig. 3 is an enlarged sectional view with parts removed showing the feed carriage construction;

Fig. 4 is a plan view with parts removed showing the structure of the wedges used to clamp the wire; and,

Fig. 5 is a diagram wherein the position of the feed "ice carriage is plotted against time as represented by the angular displacement of the crankshaft.

For a greater understanding of the present invention reference should be made to the drawings wherein A designates the nail making machine generally to which the feed mechanism embodying this invention is particularly well adapted. For the details of construction of the nail making machine generally, reference should be made to the co-pe'nding application cited above.

The nail making machine is provided with a crankshaft 10 having an eccentric 11. The crankshaft 10 I0.- tates through one revolution during each cycle of the nail making machine and is normally used to power the header slide (not shown). The rocker arm 12 is pivoted to the frame 9 of the machine and is connected to the eccentric 11 by the connecting rod 13. The rod 13 is provided with journals for pivotably attaching the rod at the eccentric l1 and the rocker arm 12. A second rocker arm 14 is pivotably mounted on-the frame 9 of the machine as at 15 and is connected to the rocker arm 12 by a second connecting rod 16 provided with journals to pivotably attach the ends. of the rod to the two rocker arms. In the preferred embodiment of this invention the rods 13 and 16 are formed of tubular members through which a tie rod extends therbyforrhcycloidal motion of the shaft 21 The-first toggle coiii-' prises a link 22 pivoted at 23 to an adjustable slide 24 which is mounted on the frame 9 of the machine, the floating link 26 pivoted on the rocker arm 14 as at 27 and on the link 22 as at 28. A second toggle is driven by the first toggle comprising the arm 31secured to the shaft 21, the floating link 32 and the link 22 wherein the floating link 32 is pivoted to the arm 31 and the link 22 as at 33 and 34. j

The gear segment 36 is attached to the shaft 21 and is arranged to drive the feed carriage 37 through the rack 38. The feed carriage .37 is mounted on the frame of the machine and is adapted to reciprocate in a horizontal plane. Rollers 39 and 41 are attached to the'carriage 37 by the pins 42 and 43 and are adapted to ride between the guide rails 44 and 46 and guide the carriage as is reciprocated.

The carriage 37 is provided with an extension 47 extending to the rear of the carriage which provides a mounting for the feed gripper assembly. The feed gripper assembly comprises a spacer 48, a lower cover plate 49 and gripper wedges 51. The spacer 48 is provided with diverging surfaces 52 which engage similar surfaces on the wedges 51. The lower cover plate 49 and the spacer 48 are bolted together by the bolts 53 and the gripper assembly is bolted to the extension 47 by the bolts 54. The holes in the extension 47 through which the bolts 54 extend are slotted to give axial adjustment of the gripper assembly relative to the extension 47. An upwardly extending lug 56 is formed on the rearward end of the spacer 48 and is provided with an axial bolt 57 which is threaded into the end of the extension 47 and provides accurate adjustment of the gripper assembly ax-ailly relative to the extension 47.. When the adjustment is made the bolts 54 must be loosened to permit the relative axial motion between the gripper assembly and the extension 47. The wire stock 61 is threaded between the gripper wedges 51 and into the machine. A pressure lever 62 is pivoted on the feed carriage 37 at 63 and is provided with upwardly extending ears 64 which engage the forward end of the wedges 51. The pressure lever 62 is also provided with a horizontally extending arm 66. The roller 67 is pivoted on the end of the lever 68which is pivoted to the frame of the machine at 63*. The lever 68 is also provided with a downwardly extending extension 71 which is pivoted to the spring guide 72 at 73. The spring sleeve 74 is threaded onto the frame of the machine and is provided with a bore 76 which extends axially around the spring guide 72. The spring sleeve 74 is provided with a nut-like portion 77 at its rearward end and facilitates the rotating of the sleeve for axial adjustment. A spring 78 is compressed between the spring sleeve 74 and the spring guide 72 and urges the roller 67 through the lever 68 against the arm 66. Due to the force of the roller 67 on the arm 66 the pressure lever 62 exerts an axial force on the wedges 51 tending to cause the wedges to clamp the wire stock 61.

A manually operated eccentric shaft 79 is mounted on the machine and is adapted to engage the rearward end of the lever 68. As the eccentric shaft 79 is rotated the lever 68 is cammed away from the pressure lever 62 thereby releasing the pressure of the spring 78 when the Wire stock is to be manually fed through the wedges 51.

The rocker arm 14 reciprooates through the angle X as the crankshaft rotates and the link 22 is driven through the angle Y by the rocker arm 14. The length of the various links and the location of the pivots is proportioned so that the pivots 15, 27 and 28 on the rocker arm 14 and the floating link 26 are substantially aligned when the rocker arm 14 is at the'rearward extreme position. It is inherent in toggles and linkages of this-nature that when the floating link approaches alignment with the driving link that the angular velocity of the driven link is gradually reduced so although the rocker arm 14 reciprocates in substantially a harmonic motion that motion is translated to the link 22 and takes the form of substantially cycloidal motion. A second toggle composed of the links 22 and 32 and the arm 31 is arranged so that the pivots 23, 33 and 34 are substantially aligned when the link 22 is in its forward position so here again the angular velocity of the arm 31 gradually decreases as the arm 31 rotates through the angle Z. The second toggle, like the first toggle, inherently transposes the motion into a cycloidal type motion due to the fact that the floating link 32 and the link 22 are substantially aligned at one end position of the reciprocation. The effect of the two toggles is to compound the motion with the result that the substantially harmonic motion of the rocker arm 14 appears as substantially cycloidal motion in the arm 31. Reference should be made to Fig. 5 wherein the angular displacement of the arm 3-1 as represented by the position of the feed carriage is plotted against rotation of the crankshaft 10.

The slide 24 is mounted for vertical adjustment on the frame of the machine and is adapted to slide in a slot formed in the bracket 81 which is mounted on the machine frame 9. A screw 82 is threaded through the bracket 81 where it is restrained from axial motion by the collar and into the slide 24 at 83, thereby providing accurate vertical adjustment of the slide 24/ A .clamp plate 86 is mounted on the opposite side of the bracket 81 and is provided with a stud 87 and a locking nut 88 for locking the slide 24 in position after the adjustment has been made.

' By adjusting the slide- 24 vertically, it is possible to changethe length of the angle Z through which the arm 31 rotates. As the slide 24 is moved upwardly by the screw 72'the pivot 23 is moved to the corresponding amount thereby increasing the size of the angle 2 through which the arm 31 rotates. Conversely, adjustment of the slide 24 and the pivot 23 downwardly reduces the size of the angle Z through which the arm 31 rotates. In this way the operator may adjust the are through which the arm 31 rotates and thereby adjust the angular rotation of the shaft 21 and the gear segment 36. Of course, changing the length of the angular displacement of the gear segment 36 changes the distance through which the carriage 37 moves and changes the amount of stock fed into the machine during each cycle. This simple sturdy structure, therefore, permits adjustment of the amount of stock fed into the machine while the machine is in operation and greatly increases the output of the machine since production does not have to be stopped while adjustments are being made.

Reference to Fig. 5 shows that the feed carriage reverses direction almost instantaneouslyat the forward end of the stroke so the inertia of the Wedges 51 tends to overcome the force of the cam roller 67 and the pressure arm 62 and causes the wedges to release the stock 61. The action of the spring 78 in urging the wedges 51 into engagement with the stock 61 is increased at the time when the stock is clamped since the lever arm of the pressurelever 62 is greatest at this moment so any possible slippage between the wedges and the stock is minimized. The above structure permits very rapid feeding of the stock without any sliding between the various parts and provides for a gradual acceleration of the feed carriage and the stock when the feeding begins thereby eleminating the tendency of the stock to bend and jam.

7 Having completed a detailed description of a preferred embodiment of the present invention so that others skilled in the art may be able to understand and practice the same, I state that what I desire to secure by Letters Patent is not limited by said preferred embodiment but rather is defined in what is claimed. i

What is claimed is:

1. Stock feed mechanism for a machine having a rotating crankshaft to drive a header slide comprising a rocker pivotally mounted on the frame of the machine, means including a pitman connecting said header slide crankshaft and said rocker to oscillate the rocker in timed relation to crankshaft rotation, an oscillating feed shaft mounted in the machine frame on an axis parallel to the pivotal axis of said rocker, an arm fixed to said feed shaft extending generally parallel to an arm on said rocker, means interconnecting said feed shaft arm and said rocker arm to impart slow acceleration to the feed shaft in a direction advancing stock into the machine and fast acceleration to the feed shaft when moved in an opposite direction comprising a block mounted for limited adjusting movement on the frame, a lever having one end thereof pivoted to said block and the other end thereof disposed intermediate the arm of the feed shaft and the said arm of the rocker, a first toggle link pivotally connecting the end of the arm on the feed shaft to the outer end of said lever, a second toggle link connecting said rocker arm and said lever at a point substantially midway of the length of said lever, a feed slide mounted for reciprocation on the frame, a gear sector fixed to said feed shaft, said feed slide having a rack in meshed engagement with said gear sector, a pair of co-operating wedges carried by the feed slide to grip the stock for advancing the same into the machine, a roller carried by the frame adjacent the path of reciprocation of the feed slide, a wedge lever pivotally mounted on the feed slide adapted to ride on said roller as the feed slide is reciprocated whereby the effective length of the wedge lever is decreased as the feed slide moves to advance stock into the machine and the effective length of said wedge lever is increased as the feed slide moves in an opposite direction.

2. Stock feeding apparatus for a machine of the type having a rotating crankshaft to reciprocate a header slide, comprising a rocker pivotally mounted on the frame of the machine, an eccentric on said crankshaft, linkage interconnecting said crankshaft eccentric and said rocker to impart oscillation to the rocker in timed relation to the crankshaft rotation, a feed shaft journaled in the heme on an axis parallel to the pivotal axis of said rocker, an arm fixed to the feed shaft extending generally parallel to an arm on said rocker, a feed stroke adjusting block mounted on the machine frame, a lever pivoted on said block and extending therefrom into a position between the arm on the feed shaft and the arm on the rocker, a first toggle connecting the end of said lever to said feed shaft arm and a second toggle connecting the intermediate portion of said lever to said rocker whereby oscillating movement of the feed arm in a stock feeding direction is characterized by a slow acceleration and oscillating motion in the opposite direction is characterized by a fast acceleration, a reciprocating feed slide mounted in horizontal guideways in the machine frame beneath said feed shaft, a gear sector on the feed shaft in mesh with a rack on said feed slide to impart slide reciprocation to intermittently advance stock into the machine, wedge grippers carried by the feed slide, a roller carried by the machine frame beneath the feed slide and a pivoted wedge lever carried by the feed slide having a portion thereof extending over and riding on said roller whereby the effective length of said lever is decreased as the slideadvances the stock into the machine and is increased as the slide moves in an opposite direction.

3. Stock feed mechanism for a machine having a rotating crank to drive a header slide comprising a rocker having a pair of angularly spaced arms, said rocker pivotally mounted on the frame of the machine, means including a pitman connecting said header slide crank and one arm of said rocker to oscillate the rocker in timed relation to crankshaft rotation, an oscillating feed shaft journaled in the machine frame adjacent said rocker, an arm fixed to said feed shaft generally parallel to the other arm on said rocker, means interconnecting said feed shaft arm and said rocker arm to impart slow acceleration to the feed shaft in one direction for advancing stock into the machine and fast acceleration to the feed shaft when moved in the other direction comprising a block adjustably mounted on the frame, a lever having one end thereof pivoted to said block and the other end thereof suspended between the arm of the feed shaft and the said other arm of the rocker, a first toggle link pivotally conmeeting the outer end of the arm on the feed shaft and the outer end of said lever, a second toggle link connecting said other rocker arm and said lever between the first toggle and said one end of said lever, a feed slide mounted for reciprocation on the frame, a gear sector fixed to said feed shaft, said feed slide having a rack in meshed engagement with said gear sector, a pair of cooperating wedges carried by the feed slide to grip the stock for advancing the same into the machine, a roller carried by the frame adjacent the path of reciprocation of the feed slide, a wedge lever pivotally mounted on the feed slide adapted to ride on said roller as the feed slide is reciprocated whereby the effective length of the wedge lever is decreased as the feed slide moves to advance stock into the machine and the effective length of said wedge lever is increased as the feed slide moves in an opposite direction.

4. Stock feeding means for a nail machine having a. rotating crankshaft to reciprocate a header slide comprising a rocker pivotally mounted on the frame of the machine, linkage interconnecting said crankshaft and said rocker to impart oscillation to the rocker in timed relation to the crankshaft rotation, a feed shaft journaled in the frame adjacent said rocker, an arm fixed to the feed shaft extending generally parallel to an arm on said rocker, a feed stroke adjusting block slidably mounted on the machine frame between the feed shaft and rocker, a lever pivoted on said block suspended between the arm on the feed shaft and the arm on the rocker by two toggle links, the first toggle link connecting the end portion of said lever to said feed shaft arm and the second toggle link connecting an intermediate portion of said lever to said rocker whereby movement of the feed arm in a stock feeding direction is characterized by a slow acceleration and movement in the opposite direction is characterized by a fast acceleration, a reciprocating feed slide having a rack, said slide being mounted in horizontal guideways in the machine adjacent said feed shaft, a gear sector on the feed shaft in mesh with said rack on said feed slide to impart slide reciprocation to intermittently advance stock into the machine, co-operating grippers carried by the feed slide, a roller carried by the machine frame adjacent the feed slide, a pivoted grip operating lever carried by the feed slide, said lever having a horizontal portion thereof in contact with said roller whereby the distance between the roller and the lever pivot is decreased as the slide advances the stock into the machine and said distance is increased as the slide moves in an opposite direction.

References Cited in the file of this patent UNITED STATES PATENTS 1,195,384 Mottlau Aug. 22, 1916 1,376,668 Blomberg et al. May 3, 1921 2,056,402 Klocke Oct. 6, 1936 2,381,171 Little et al. Aug. 7, 1945 

